Checking Fuel Pressure

Checking Fuel Pressure

Tools

Checking fuel pressure

DANGER:
Working on the fuel system.
- Danger of fatal injury and damage to property.

- Safety instructions must be observed at all times.

3. Screw off cap -arrow- on the fuel filter test connection.

4. Connect pressure gauge pressure gauge P378a to the connecting line 9705/2 and screw the line onto the valve by hand (knurled nut).
5. PIWIS Tester 9718 with the adapter line must be connected to the input socket in the vehicle. Switch on ignition and switch off all loads (radio, air conditioning, etc.).

6. Switch on the Porsche PIWIS Tester 9718, select Diagnosis and then highlight the vehicle 911 (997).

7. Run the individual control unit search for the engine control unit. To do this, select DME with the tracer pen and press F12>>.

INFORMATION:
- The fuel system of the 997 Turbo, 997 GT2 and 997 GT3 has two electric fuel pumps (EKP).
- The delivery rate volume and supply pressure of these pumps must be checked individually.
- These can be activated individually in the PIWIS Tester 9718.

8. Select the Drive links item and then select fuel pump relay 1 with the tracer pen.

8.1 Press F8=Start to activate fuel pump 1 (EKP 1).

9. Read off pressure shown on pressure gauge.
Nominal value with the engine off: 3.9 ± 0.3 bar

9.1. Deactivate the fuel pump by pressing F8=Stop.

10. Repeat the process for fuel pump 2 (EKP 2).
Nominal value with the engine off: 3.9 ± 0.3 bar

11. Switch off ignition, switch off Porsche System Tester and disconnect adapter line in the passenger compartment.

12. Remove pressure gauge.
12.1. Wrap a cloth around the test connection to absorb emerging fuel. Wear fuel-resistant protective clothes and goggles.
12.2. Loosen and unscrew knurled nut on connecting line and remove pressure gauge.
12.3. Screw protection cap onto the valve and tighten hand-tight.

Fuel system holding pressure

DANGER:
Working on the fuel system.
- Danger of fatal injury and damage to property.

- Safety instructions must be observed at all times.

1. Attach or mount a warning sign in a clearly visible position on the vehicle.

INFORMATION: The battery voltage must not fall below 11 volts during the check.

2. Check the battery charge state using a voltmeter or the Porsche PIWIS Tester 9718 (Supply voltage menu item).
Connect a battery charger if necessary.

INFORMATION:
- The fuel system of the 997 Turbo, 997 GT2 and 997 GT3 has two electric fuel pumps (EKP).
- The delivery rate volume and supply pressure of these pumps must be checked individually.
- These can be activated individually in the PIWIS Tester 9718.

3. Connect pressure gauge in the same way as for the supply pressure test.
3.1. Activate fuel pump 1 (EKP 1) in the same way as for the supply pressure test until the nominal value 3.9 ± 0.3 bar is reached.
3.2. Check holding pressure.
Nominal value after one hour: 2 bar

4. Repeat the test for fuel pump 2 (EKP 2).
5. Switch off ignition, switch off Porsche System Tester and disconnect adapter line in the passenger compartment.

6. Remove pressure gauge.
6.1. Wrap a cloth around the test connection to absorb emerging fuel. Wear fuel-resistant protective clothes and goggles.
6.2. Loosen and unscrew knurled nut on connecting line and remove pressure gauge.
6.3. Screw protection cap onto the valve and tighten hand-tight.